1. Technical Field of the Invention
The present invention relates to comixtures of dextran sulfate and escin for preventively or curatively treating skin redness and/or skin edema and/or sensitive skin, particularly redness and/or edema around the eyes and most particularly bags and/or dark rings around the eyes.
2. Description of the Prior Art
The human body in general is sensitive to the external attacking factors or challenges of modern life (exposure to UV radiation, large variations in hygrometry and temperature, pollution, etc.). The response to these challenges may be reflected, inter alia, by the appearance of redness associated with a local vasodilation or by the appearance of local edema.
In the field of skin disorders, it is known that certain skin types are more sensitive than others to external attacking factors.
The assignee hereof has now determined that the symptoms associated with sensitive skin are, in particular, subjective signs, which are essentially dysaesthetic sensations. By the expression xe2x80x9cdysaesthetic sensationsxe2x80x9d are intended more or less painful sensations experienced in an area of skin, such as stinging, tingling, itching or pruritus, burning, heating, discomfort, tautness, etc., in response to various factors such as the environment, the emotions, foods, the wind, friction, shaving, soap, surfactants, hard water having a high calcium concentration, temperature variations, or wool.
Due to its structure and its high innervation, the area around the eyes is an anatomical region which is particularly sensitive to attacking factors or to behavioral mechanical stresses (friction). Following these stimuli and on account of a very low internal threshold of neurogenic sensitivity in certain more sensitive individuals, the area around the eyes rapidly shows evidence by redness and/or itching, which are the consequences of an exacerbated vasodilation, of a passing discomfort, but also by bags and/or dark rings and/or edema, of more persistent discomfort reflecting a greater metabolic depletion of the epidermis and the dermis.
Other than these physiological data, it is known that simply from their cosmetic appearance, redness, dark rings and bags have always been considered as unattractive and need continues to exist for means to mask or even eliminate same.
It has now surprisingly and unexpectedly been determined that comixture of dextran sulfate and escin elicits noteworthy calmant and/or vasodilation-inhibitory and/or anti-edema properties, these properties being developed in proportions which exceed the simple cumulation of the effects obtained with each of the components taken individually.
More particularly according to the present invention, dextran is a neutral polysaccharide with no charged moieties, which is biologically inert, and which is prepared by fermenting beet sugar containing only hydroxyl groups. It is possible to obtain dextran fractions of different molecular weights from native dextran by hydrolysis and purification. Too, dextran can be in the form of dextran sulfate.
Other than the physicochemical properties of dextran sulfate which are known to this art and which make it a good compound for cosmetic compositions (good solubility in water and saline solutions, high stability in solutions of pH ranging from 4 to 10 at room temperature), it is also known that dextran sulfate has properties of water absorption, a protective effect against the damage induced by free radicals, particularly in topical application, stabilization of proteins or unstable species and substances, and moisturization on account of its excellent hydrophilic properties. Biological properties such as an anti-coagulant effect, an inhibitory effect on enzymes such as hyaluronidase, glucosidases, elastase or even thrombin, and antiviral activity are also known.
As regards the skin and skin protection, dextran sulfate is known for its anti-wrinkle, anti-inflammatory, anti-allergic and anti-aging properties and for its role in treating rough and flaky skin and in moisturization.
Escin is a chemical molecule consisting of glucuronic acid and two sugars (glucose-xylose) linked to an aglycone, deglucoescin which has a molecular weight of 1131.24. This is a molecule which exists, for example, in plant extracts, particularly in extracts of common horsechestnut. In the prior art, escin is described in weight-reducing compositions (FR-2,729,856, EP-034,153, WO-97/42928 and WO-98/15259), in compositions for promoting blood circulation (EP-158,090 and U.S. Pat. No. 4,983,626), in compositions for treating the skin such as anti-inflammatory agents (EP-728,472), for improving the cohesion between the dermis and the epidermis (WO-98/19664) and in skin-lightening cosmetic compositions (JP-07,076,512).
It is also known to the prior art to formulate escin in compositions for treating bags and wrinkles under the eyes (FR-2,668,061, U.S. Pat. No. 5,273,916 and U.S. Pat. No. 5,571,503).
However, to date it is believed that the surprising synergistic effect exhibited by the intimate admixture of escin and dextran sulfate on the inhibition of the vasodilation and/or the anti-edema effect and/or the soothing of sensitive skin was unknown to this art.
Thus, the present invention features a comixture comprising, as active agent, formulated into a physiologically acceptable medium, intimate immixture of dextran sulfate and escin.
By the expression xe2x80x9cphysiologically acceptable mediumxe2x80x9d is intended a medium which is compatible with the skin, mucous membranes, the nails and the hair.
According to the invention, the composition preferably comprises dextran sulfate, in the form of a sodium salt thereof.
According to the invention, the dextran sulfate has a molecular weight ranging from 2xc3x97103 to 5xc3x97106 and preferably from 5xc3x97103 to 105.
Too, the dextran sulfate can be of any origin. The compositions of the invention preferably comprise dextran sulfate marketed by Pharmacia Biotech under the trademark Dextran sulfate 10 sodium salt(copyright).
The compositions of the invention comprise escin which can be of synthetic or natural origin.
By the expression xe2x80x9csynthetic originxe2x80x9d is intended escin, in pure form or in solution, irrespective of its concentration in said solution, obtained by chemical synthesis. The expression xe2x80x9cnatural originxe2x80x9d connotes escin, in pure form or in solution, irrespective of its concentration in said solution , obtained from a natural element such as, for example, a plant extract, particularly an extract of common horsechestnut.
According to the invention, the composition preferably comprises escin marketed by the company Indena under the trademark escin 3030000(copyright) or, alternatively, escin marketed by the company LEK under the trademark amorphous beta Aescin(copyright).
The amounts of dextran sulfate and of escin formulated into the compositions of the invention obviously depend on the desired effect.
For example, the amount by weight of dextran sulfate which are included in the compositions of the invention advantageously range, for example, from 0.01% to 5% and preferably from 0.05% to 2% relative to the total weight of the composition.
To provide an order of magnitude, the amount by weight of escin formulated according to the invention advantageously constitutes from 0.005% to 5% relative to the total weight of the composition, preferably from 0.01% to 2% relative to the total weight of the composition.
In the compositions of the invention, the weight ratio between the dextran sulfate and the escin advantageously ranges from 2xc3x9710xe2x88x923 to 103 and preferably from 25xc3x9710xe2x88x923 to 200.
Although they can be formulated for any application, the compositions of the invention are preferably formulated for topical application.
The compositions of the invention can be for cosmetic or dermatological applications. According to the invention, the composition is preferably a cosmetic composition and even more preferably a cosmetic composition for topical application.
The present invention thus features comixture of dextran sulfate and escin for preventively or curatively treating skin redness and/or skin edema and/or sensitive skin.
The clinical signs of sensitive skin are essentially subjective: stinging, tingling, pruritus, tautness and heating, and they are occasionally associated with erythema.
Too, this invention features compositions of dextran sulfate and escin for preventively or curatively treating stinging and/or tingling and/or pruritus and/or tautness and/or heating and/or erythema.
As indicated above, the area around the eyes is particularly sensitive to external attacking factors or influenced.
Accordingly, this invention also features comixtures of dextran sulfate and escin for preventively or curatively treating redness and/or edema around the eyes.
Similarly, this invention features compositions comprising comixture of dextran sulfate and escin for preventively or curatively treating bags and/or dark rings around the eyes.
The compositions according to the invention comprise a cosmetically acceptable support (vehicle, diluent or carrier), i.e., a support which is compatible with the skin, mucous membranes, the nails and the hair and which can be in any pharmaceutical form normally employed for topical application, in particular in the form of an aqueous, aqueous alcoholic or oily solution, an oil-in-water or water-in-oil or multiple emulsion, an aqueous or oily gel, a liquid, an ointment, pasty or solid anhydrous product, a dispersion of oil in an aqueous phase with the aid of spherules, it being possible for these spherules to be polymer nanoparticles such as nanospheres and nanocapsules or, more preferably, lipid vesicles of ionic and/or nonionic type.
Such compositions may be more or less fluid and may have the appearance of a white or colored cream, an ointment, a milk, a lotion, a serum, a paste or a mousse. Same can optionally be topically applied onto the skin in the form of an aerosol. Same can also be in solid form and, for example, be in the form of a stick. These can be used as a care product, as a cleansing product, as a makeup product or as simple deodorant product.
In known fashion, the compositions of the invention can also contain adjuvants and additives that are conventional in cosmetics and dermatology, such as hydrophilic or lipophilic gelling agents, hydrophilic or lipophilic active agents, preservatives, antioxidants, solvents, fragrances, fillers, UV-screening agents, pigments, colorants, chelating agents, odor absorbers and dyestuffs. The amounts of the various adjuvants and additives are those conventionally employed in the fields considered, and, for example, advantageously range from 0.01% to 20% relative to the total weight of the composition. Depending on their particular nature, these adjuvants and additives can be introduced into the fatty phase, into the aqueous phase, into the lipid vesicles and/or into the nanoparticles.
When the compositions of the invention are emulsions, the proportion of the fatty phase advantageously ranges from 5% to 80% by weight, and preferably from 5% to 50% by weight, relative to the total weight of the composition. The oils, emulsifiers and co-emulsifiers formulated into the composition in emulsion form are selected from among those conventionally included in the field considered. The emulsifier and co-emulsifier are advantageously present in the composition in a proportion ranging from 0.3% to 30% by weight, and preferably from 0.5% to 20% by weight, relative to the total weight of the composition.
Exemplary oils according to the invention include mineral oils, oils of plant origin (apricot oil, sunflower oil), oils of animal origin, synthetic oils, silicone oils and fluoro oils (perfluoropolyethers). Fatty alcohols (cetyl alcohol), fatty acids and waxes (beeswax) are also representative fatty substances.
Exemplary emulsifiers and co-emulsifiers suited for the invention include fatty acid esters of polyethylene glycols such as PEG-40 stearate and PEG-100 stearate, and fatty acid esters of polyols, such as glyceryl stearate and sorbitan tristearate.
Exemplary hydrophilic gelling agents include, in particular, carboxyvinyl polymers (carbomer), acrylic copolymers such as acrylate/-alkylacrylate copolymers, polyacrylamides, polysaccharides, natural gums and clays, and exemplary lipophilic gelling agents include the modified clays such as bentones, metal salts of fatty acids, hydrophobic silica and polyethylenes.
The subject compositions can also contain other hydrophilic active agents, such as proteins or protein hydrolysates, amino acids, polyols, urea, allantoin, sugars and sugar derivatives, water-soluble vitamins, plant extracts and hydroxy acids.
And exemplary lipophilic active agents include retinol (vitamin A) and derivatives thereof, tocopherol (vitamin E) and derivatives thereof, essential fatty acids, ceramides, essential oils, and salicylic acid and derivatives thereof.
It is also envisaged to formulate into use in the composition of the invention, in addition to the escin/dextran sulfate comixture, compounds or species selected from among:
(a) plant hormones;
(b) calcium antagonists, such as verapamil and Diltiazem;
(c) OH-radical scavengers, such as dimethyl sulfoxide;
(d) chlorine-channel openers;
(e) plant extracts such as those from Iridacea and Rosacea plants or from soybean, these extracts possibly containing isoflavones;
(f) extracts of microorganisms including, in particular, bacterial extracts such as those of non-photosynthetic filamentous bacteria.
Other compounds or species can also be included in the above list, for example, potassium-channel openers such a diazoxide and minoxidil, spiroxazone, phospholipids such as lecithin, linoleic acid, linolenic acid, salicylic acid and derivatives thereof described in FR-2,581,542, such as salicylic acid derivatives bearing an alkyl group having from 2 to 12 carbon atoms in position 5 of the benzene ring, hydroxycarboxylic acids or keto carboxylic acids and their esters, lactones and their corresponding salts, anthralin, carotenoids, eicosatetraenoic acid and eicosatrienoic acid or their esters and amides, and vitamin D and its derivatives thereof.
In another embodiment of the invention, other active agents suited, in particular, for preventing and/or treating skin complaints or afflictions can be formulated into the subject compositions. Exemplary such active agents include:
(i) agents which modify skin differentiation and/or proliferation and/or pigmentation, such as retinoic acid and its isomers, retinol and its esters, vitamin D and its derivatives, estrogens such as estradiol, kojic acid or hydroquinone;
(ii) antibacterial agents such as clindamycin phosphate, erythromycin or antibiotics of the tetracycline class;
(iii) agents which modify the adhesion of bacteria to the skin and/or mucous membranes, such as honey, in particular acacia honey and certain sugar derivatives;
(iv) anti-parasitic agents, in particular metronidazole, crotamiton or pyrethroids;
(v) antifungal agents, in particular compounds belonging to the imidazole class such as econazole, ketoconazole or miconazole or their salts, polyene compounds such as amphotericin B, compounds of the allylamine family such as terbinafine, or octopirox;
(vi) antiviral agents such as acyclovir;
(vii) steroidal anti-inflammatory agents, such as hydrocortisone, betamethasone valerate or clobetasol propionate, or nonsteroidal anti-inflammatory agents such as ibuprofen and its salts, diclofenac and its salts, acetylsalicylic acid, acetaminophen or glycyrrhetinic acid;
(viii) anaesthetics such as lidocaine hydrochloride and derivatives thereof;
(ix) anti-pruriginous agents such as thenaldine, trimeprazine or cyproheptadine;
(x) keratolytic agents such as alpha- and beta-hydroxy carboxylic acids or beta-keto carboxylic acids, their salts, amides or esters and more particularly hydroxy acids such as glycolic acid, lactic acid, salicylic acid, citric acid and fruit acids in general, and 5-n-octanoylsalicylic acid;
(xi) free-radical scavengers such alpha-tocopherol or its esters, superoxide dismutases, certain metal-chelating agents or ascorbic acid and its esters;
(xii) anti-seborrhoeic agents such as progesterone;
(xiii) anti-dandruff agents such as octopirox or zinc pyrithione;
(xiv) anti-acne agents such as retinoic acid or benzoyl peroxide;
(xv) substances and substrates such as substance P antagonists, CGRP antagonists or bradykinin antagonists or NO-synthase inhibitors or sodium-channel inhibitors, these compounds being described as being active in the treatment of sensitive skin and as having anti-irritant effects, in particular with respect to irritant compounds which may be present in the compositions;
(xvi) agents suited for modulating the skin""s allergic response, such as LPV.
Active agents which can be formulated into the composition of the invention include, in particular, moisturizers such as polyols (for example glycerol), vitamins (for example D-panthenol), anti-inflammatory agents, calmants (allantoin and cornflower water), UVA and UVB screening agents, matt-effect agents (for example the partially crosslinked polydimethylorganosiloxanes marketed under the trademark KSG(copyright) by Shin-Etsu) and mixtures thereof.
Anti-wrinkle agents can also be added, and in particular tensioning products such as plant proteins and their hydrolysates, in particular the extract of soybean proteins marketed under the trademark Eleseryl(copyright) by the company LSN or the oat derivative marketed under the trademark Reductine(copyright) by the company Silab.
The present invention also features a cosmetic regime/regimen for treating skin redness and/or edema and/or sensitive skin, particularly redness and/or edema around the eyes, most particularly bags and dark rings around the eyes, comprising topically applying intimate immixture of dextran sulfate and escin, or composition comprised thereof, onto the skin.
The method or regime/regimen of the invention is a cosmetic treatment since it improves the individual""s aesthetic appearance.
The cosmetic regime/regimen of the invention is advantageously carried out, in particular, by topically applying the subject compositions according to the usual technique for administering such compositions. For example: topical application of creams, gels, sera, ointments, lotions, milks, mousses, shampoos or sunscreen compositions onto the skin and/or the hair, or, alternatively, application of toothpaste onto the gums.